Here is an article from the Guardian with more detail about the eruption:

— start quote — Mount Aso, a volcano on Japan’s main southern island of Kyushu, erupted on Monday, Japan’s Meteorological Agency said, blasting a plume of black smoke 2km (1.2 miles) high, but there were no immediate reports of damage or injuries. The 1,592-metre (5,222ft) Mount Aso is one of the most active peaks in Japan but is also a popular hiking spot. There were a handful of people at a parking lot near the peak but they were being evacuated safely, officials said. — end quote —

Please read the rest of the article on line.

http://www.theguardian.com/world/2015/sep/14/japanese-volcano-mount-aso-on-island-of-kyushu-erupts